grassello 600

Over the years, the grassello di calce has been extremely important in coating old historic buildings, improving their appearance and creating an effective protective layer for the plaster and brickwork.
The Colorificio Veneziano has perfected a product that maintains the features of the old lime coating, updated to the modem needs of building work.
The grassello di calce undergoes very long seasoning, by baking carefully selected calcareous stones. For the stone to become an aerial bond in the paste, it must first be baked in special ovens and then turned off.
Baking lasts around 20 hours at 900°C, during this process, which is called decarbonation, the stones give off the water and carbon dioxide they contain.
Decarbonation transforms the stone from calcium carbonate into calcium oxide, i.e. burnt lime.
The burnt lime that is formed Is turned off by immersing it in fresh water: this process is called hydration and causes an exothermic reaction, i.e. a great deal of heat is developed. This is when it transforms from calcium oxide to calcium hydrate.
The reaction is very long to allow the formation of crystals with the required binding properties.